April 30, 2012 -- The number of U.S. babies born dependent on drugs nearly tripled between 2000 and 2009, researchers reported today.

Drug dependence occurs when a person develops a physical dependence on a drug, leading to withdrawal symptoms if the drug is abruptly stopped. Newborns can be drug dependent, but do not have the harmful behavior typically seen with
addiction. By 2009, an estimated 13,539 babies -- an average of one an hour -- were diagnosed with a drug withdrawal syndrome, which most commonly occurs because their mothers were taking opiate drugs, or narcotics, while pregnant, according to the new study.

"We were surprised by the magnitude of the increase," says researcher Stephen Patrick, MD, MPH, a Robert Wood Johnson clinical scholar at the University of Michigan.

Patrick and his collaborators used national inpatient databases to find the number of women who were taking opiates when they gave birth and the number of babies born with drug dependency.

"These babies, compared to other babies, are more likely to be irritable and inconsolable," says Patrick, a neonatologist. "They'll likely be born low birth weight. Feeding issues are common."

The use of prescription opiate painkillers such as Oxycontin and Vicodin has increased four-fold over the last decade, according to a recent report from the CDC. Patrick's study found a five-fold increase in opiate use among pregnant women.

'Overprescribed'

"These medications provide superior pain control for cancer and chronic pain, but have been overprescribed, diverted, and sold illegally, creating a new opiate addiction pathway and a public health burden for maternal and child health," Marie J. Hayes, PhD, a University of Maine psychologist, and Mark Brown, MD, a Bangor, Maine, pediatrician, write in an editorial accompanying Patrick's study.

A 2010 survey by the Substance Abuse and Mental Health Services Administration found that 16.2% of pregnant teens and 7.4% of pregnant women 18 to 25 years old used illicit drugs, including opiates such as heroin and illegally obtained prescription painkillers.

Although the new study did not have information about which opiates women took during pregnancy and why, Patrick says: "It's probably all comers. Some women were using opiates appropriately for chronic pain or in methadone clinics." Methadone is often used to treat heroin addiction.

Not all babies exposed to opiates in the womb will be born dependent on drugs, Patrick says, which probably explains why the percentage of pregnant women who used the drugs increased more than that of babies born with drug dependence.

About 60% to 80% of babies who were exposed to heroin or methadone in the womb will experience withdrawal after birth, he says. But women who have an opiate dependence shouldn't try to quit taking opiates abruptly while pregnant, he says, because withdrawal in the womb "can be dangerous for both mom and baby."

Generally, babies born in withdrawal are treated with oral morphine or methadone, Patrick says, but surveys show that treatment varies around the country. "I think we need more research dollars for studies on how to best take care of these babies." In some hospitals, they might spend the entire time in the neonatal intensive care unit, he says, while in others they might go straight to the general pediatric floor.

On average, the cost of treating each of these babies was $53,400 in 2009, a 35% increase over 2000, although their length of stay in the hospital, 16 days, remained the same, the researchers found.

Burden on States as Well as Patients

''Four out of five such babies were insured by Medicaid, a program funded by the federal government and the states to cover low-income individuals. That's one reason "my hope is that this will get attention outside of neonatologists," Patrick says.

States have started to pay attention, he says. More than 30 have registries to try to identify people who might be "doctor shopping," or seeking opiate prescriptions from multiple doctors.

In addition, Florida lawmakers this year established a statewide task force on prescription drug abuse and newborns. Task force members, charged with examining the scope of the problem, the cost of caring for affected babies, long-term effects, and prevention strategies, include the state's attorney general and surgeon general.

Patrick presented his research at the Pediatric Academic Societies annual meeting in Boston, and the Journal of the American Medical Association posted it early online.